THE WILDLIFE ARK TRUST

Site navigation

Red Squirrel

Patrons

The Problem

Even under normal circumstances, red squirrels struggle
to find food in the spring and summer months and this can result in breeding
failure and even death. When the larger, more aggressive grey squirrel
is added to the equation, the situation becomes intolerable. Living in
higher densities than the reds and able to exploit food sources more
efficiently, it is easy to understand why the greys are taking over.
In addition, the greys carry a disease, the squirrelpox virus, to which
they are immune, but which ensures a painful lingering death for any
red which
becomes infected. That is why the Trust agrees wholeheartedly with Doctor
Craig Shuttleworth in his report, 'Grey Squirrel control on the Island
of Anglesey 1998 - 2004', which begins with the statement, ‘Grey
Squirrel Sciurus carolinensis control is the single most important factor
in
the conservation of the red squirrel Sciurus vulgaris populations within
woodlands where the two species of squirrel occur together. Research
has demonstrated, and regional red squirrel extinctions illustrated,
that it is paramount that contact between red and grey squirrels is minimised.’.

Over time prey species develop strategies to evade predators.
The water vole is no different and had a number of ways it would escape
from the native predators. If it was feeding on land, it could escape
a fox by going down its burrow. When threatened in its burrow by a weasel,
it could avoid attack by diving into the water and, when in the water,
if a heron became a threat it could retreat again to its burrow. The
arrival of the American mink changed all that overnight. The mink can
hunt and kill water vole everywhere, on riverbanks, in their burrows
and in the water. Evasion tactics developed over thousands of years no
longer worked. The water vole now has nowhere to hide. Sir David Attenborough
summed up the situation in the BBC’s ‘Wildlife on One’, “…When
mink invade a stretch of river, they quickly reduce the number of vulnerable
creatures such as duck and water voles….Since their invasion of
rivers and streams across Britain, mink have wiped out many water vole
communities and will continue to do so unless their own numbers are controlled”.